Dead-locking jamb bolt



Jan. 12, 1960 w. P. JENKINS DEAD-LOCKING JAMB BOLT Filed Oct. 29, 1956 66 Q U :9? g -60 L .54 A, l 50 z jg 4 a zen HTTOPMEYS.

the bolt is in erect position.

United States Patent F DEAD-LOCKING JAMB BOLT William P. Jenkins, Kailua, Oahu, Hawaii Application October 29, 1956, Serial No. 618,946 8 Claims. Cl. 292-67) This invention relates to a jamb bolt which, when in projected position, is locked against retraction until released by proper manual operation.

Jamb bolts are used to block opening movement of sliding panels, such as door or window panels, especially where there are a plurality of such panels which slide past each other on adjacent parallel tracks in an exterior wall. Commonly, the jamb bolt consists of a bolt pivotally mounted in a housing countersunk in the face of a panel or jamb, and arranged to tilt between a retracted or flush position in which it presents no obstruction to movement of the adjacent panel, and a projected or erect operative position in which it blocks movement of the adjacent panel from closed position.

The bolt is commonly biased to its two positions, as by an over-center spring. It is thus only yieldingly held against retraction, and it may be forced to its retracted position by means of a blade-like instrument inserted through the necessary clearance space along the face of the locked panel. If the spring is made heavier to resist such forcing, the bolt is more difficult to operate in its intended manner, and is objectionable (especially to women) for this reason.

It is the object of this invention to provide means to dead-lock jamb bolts against such forcing or unauthorized operation. It is a further object to thereby permit the use of lighter springs and provide easier operation. It is a further object of the invention to provide means which will lock the jamb bolts in erect position, to prevent forcing, but which will bereadily released upon proper manual operation. It is a further object of the invention to provide a jamb bolt which has both pivotal movement and movement generally longitudinally of itself, and to provide locking means which engages when the bolt is pivoted to projected position and which is released by longitudinal displacement movement, and which upon such release, permits the bolt to be freely pivoted to retracted position.

In accordance with the invention, a jamb bolt of generally conventional size and configuration is mounted in a housing both for pivotal movement between depressed and erect positions, and in addition is arranged to have limited radial displacement motion, preferably motion longitudinally of itself with respect to its housing. Conveniently, the bolt is provided with a pair of end and bottom faces extending tangentially with respect to the pivot axis, against which a leaf spring bears to form an over-center relationship and tending to hold the bolt in its retracted and operating positions. Such spring desirably underlies the bolt and tends to move it in a displacement direction to take up its lost motion, especially when To provide for dead-locking the bolt in erect position, interlocking means are provided, which engage as the bolt is moved from retracted to erect position, and which can be disengaged only by movement of the bolt longitudinally of itself when in erect position. Accordingly, the bolt may be retracted by pushing it inward and then pivoting to depressed position. Since 2,920,914 Patented Jan. 12, 1960 the necessary inward movement cannot be effected with a blade instrument inserted through a clearance space, the bolt is effectively dead-locked against tampering from the exterior side of the panel with which it is used.

In one modification, the bolt is provided with a laterally extending pin which rides in a shaped slot at one or both sides of the housing. The slot has a radial keeper portion in which the pin is received when the bolt is erect, to lock the bolt against pivotal movement. The outer end of the radial portion of the slot connects with an arcuate portion which the pin may enter when the bolt is displaced longitudinally of itself, and in which the pin moves freely as the bolt is then pivoted to retracted position. The pin and the keeper portion of the slot are positioned to be urged to locking engagement by the bolt-biasing spring. In a second modification, the

interlocking means is in the form of a tongue and groove respectively formed between the pivot pin and the wall of its bearing hole, which interlock under the influence of-the spring but release and permit free pivotal movement of the bolt when the bolt is moved longitudinally of itself against the spring. In a third modification, the bolt and its associated spring are formed to interlock when the bolt lies in erect projected position, and to release when the bolt is first displaced longitudinally.

The accompanying drawing illustrates the invention. In such drawing:

Fig. 1 is a horizontal section showing the overlapping edges of a pair of sliding panels, with a jamb lock mounted in one and a striker plate in the other;

Fig. 2 is a section on the line 22 of Fig. 1;

Fig. 3 is a side elevation, with parts broken away, of the embodiment of the invention shown in Fig. 1, and in which the dead-locking function is obtained by a pin and shaped-slot arrangement;

Fig. 4 is a longitudinal section of a jamb lock in which the dead-locking function is obtained by interengaging means between the bolt and its biasing spring;

Fig. 5 is a front elevation of the jamb lock of Fig. 4, with the bolt in retracted position;

Fig. 6 is a longitudinal section of a jamb lock in which the dead-locking function is obtained by tongue and groove interlocking between the pivot pin and the pivot hole;

Fig. 7 is a front elevation of the jamb lock of Fig. 6, with the bolt in erect position; and

Fig. 8 is a partial section similar to Fig. 6, on an enlarged scale.

Fig. 1 illustrates the use of jamb locks. A sliding panel 10 is movable edgewise of itself (downward in Fig. 1) with respect to a parallel panel 12, which may be either a fixed panel or one which is itself movable edgewise of itself. A jamb lock housing 14 is mounted in the face 16 of the panel 12, and has a bolt 18 which in operative position stands outward from the panel 12 in the path of, and preferably closely adjacent to, a strike plate 20 on the panel 10. The erect bolt 18 thus forms an obstruction preventing movement of the panel 10 in a direction of increased overlap of the panel 12. Assuming the panel 10 to be closed, and the panel 12 to be fixed, the erect bolt prevents opening of the panel 10. The bolt 18 is pivoted in the body 14, as on a pivot pin 22, and is yieldingly held in projected position by the top leaf of a U-shaped spring 24 bearing against its flat butt end 26.

To release the bolt, it is pivoted about the pivot pin and the spring then urges the bolt to retracted position.

In such retracted position, as shown in dotted lines in Fig. 3, the spring bears against the bottom face of the bolt to hold the bolt retracted.

As is seen in Figs. 1-3, the bolt housing is a box-like structure with a mounting flange at its open side. Its side walls 28 support the pivot pin 22 for the bolt 18, and its bottom wall 30 supports the bottom leg of the U-shaped leaf spring 24. Conveniently, the housing 14 may be formed to provide a pair of side bosses 32 to center the spring 24 and with a pair of bosses 34 which interengage notches in the spring 24 to locate that spring in the housing.

In the embodiment of the invention shown in Figs. 2 and 3, the pivot-pin hole 36 in the bolt 18 is elongated in a direction generally longitudinally of the bolt 18. When the bolt is in erect position, the spring 24 urges the bolt outward, to take up the lost motion permitted by the elongated pin hole 36.

To provide for dead-locking the bolt in erect position, it is provided at one or both sides with a lock pin 40 positioned between the pivot pin hole 36 and the inner end 26 of the bolt 18, and a shaped slot is formed in one (or each) side wall 28 of the housing to receive and cooperate with that pin 40. The slot includes a keeper portion 42 which extends radially and downward from the axis of the pivot pin, and an arcuate portion 44 which joins the keeper portion 42 at its outer end and which extends generally in an are about the axis of the pivot pin 22. When the bolt is in erect position, as shown in full lines in Fig. 3, with its lost motion taken up by the pressure of the spring 24 against its end 26, the lock pin 40 lies in the radial keeper portion 42 of the slot, and locks the bolt 18 against pivotal movement about the pin 22.

To retract the bolt, it is first manually thrust inward against the bias of the spring 24, such movement being permitted by the lost motion between the pivot pin 22 and its pivot hole 36; and such movement carries the lock pin 40 to the arcuate portion 44 of the slot, to release the pin 40 from its locking position, and to permit the bolt 18 to be pivoted to retracted position. During such pivotal movement the lock pin 40 moves in the arcuate portion 44 of the shaped slot. The arcuate portion 44 of the keeper slot may lie in a true arc about the axis of the pivot pin 22, in which case the bolt will be held in longitudinally displaced position with the pin 22 in the outer end of the elongated pin hole 36. Alternatively, the arcuate slot 44 may be arranged as a helix about the pivot pin 22, with its outer end closer to the pivot pin 22. In such case, the bolt 18 will move longitudinally as it pivots, and in the fully retracted position of the bolt, the pin 22 will lie at the inner end of the elongated pivot hole 36.

When the bolt 18 is again raised to erect position, the lock pin 40 travels along the arcuate portion 44 of the slot, and then moves into the radial portion of that slot under the influence of the spring 24, to automatically lock the bolt in erect position.

In the modification shown in Figs. 4 and 5, deadlocking of the bolt 18 is effected by providing such bolt with a latch boss 50 on its butt end 26, and forming a keeper slot 52 in the free leg of the leaf spring 24. As in the previous modification, the pivot hole 36 for the pivot pin 22 is elongated to permit longitudinal lost motion movement of the bolt 18. In Fig. 4, such elongation is in a direction at a slight angle to the longitudinal center line of the bolt 18, so that when the bolt is in retracted position the slot 36 has a camming efiect which, under the pressure of the biasing spring 24 tends to move the bolt 18 in a direction to take up its lost motion.

When the bolt 18 as shown in Fig. 4 is in erect position, as shown in full lines, the free leg of the spring 24 lies flat against the butt end 26 of the bolt 18, with the latch boss 50 received in the keeper slot 52, and this interengagement prevents pivotal movement of the bolt 18 toward retracted position. When it is desired to retract the bolt, the bolt is thrust inward through the lost motion provided by its elongated pivot hole, and in such movement the heel 27 of its end face 26 depresses the free leg of the spring 24, moving that leg angularly, as shown in dotted lines in Fig. 4, to carry its keeper slot 52 out of engagement with the latch boss 50. The dead-lock is thus released by lengthwise displacement of the bolt 18, and such bolt in its displaced position is free to be pivoted to its retracted position. In the retracted position, the free leg of the spring 24 presses against the lower face of the bolt 18 both to retain it in retracted position and to cooperate With the camming function of the angularly elongated pin hole 36 and move the bolt in a direction to take up its lost motion on the pivot pin 22.

In a modification shown in Figs. 6-8, the dead-locking interengagement'is eflected between the fixed pivot pin 54 and the walls of the elongated pin hole in the jamb bolt 58. The pivot pin is a generally cylindrical pin with concentric cylindrical top and bottom surfaces 60 but with its sides cut away to form flat side surfaces 62. The side surfaces 62 may lie at an angle to each other, converging toward the bottom of the housing, but preferably are substantially parallel surfaces. The pivot pin hole is generally key-hole shaped, and has a main cylindrical portion 64 and a side slot portion 66 extending toward the butt end 57 of the bolt 58. The slot 66 is of slightly greater width than the thickness between the two side faces 62 of the pivot pin 54.

When the bolt 58 is in erect position as shown in full lines in Fig. 8, the slot 66 portion of the pin hole is aligned edgewise with the flattened pivot pin 54, and the biasing spring 24 urges the bolt 58 outward to engage that slot with that pin. There is thus a tongue-andgroove interengagement between the fixed pivot pin 54 and the bolt 58, which prevents pivotal movement of the bolt 58. When it is desired to retract the bolt 58, the bolt is first thrust inward, to move it longitudinally of itself, and release the pin 54 from the notch 66 and dispose the pin 54 in the cylinder portion 64 of the pin hole. The bolt 58 can then be freely pivoted to its retracted position.

I claim as my invention:

1. A dead-locking jamb bolt, comprising a box-like housing adapted to be flush-mounted in the face of a jamb, a bolt pivotally movable in said housing between an erect position in which it stands out from the jamb and a depressed position in which it lies within the boxlike housing below the jamb face, said bolt also having limited movement longitudinally of itself when in erect position, locking means between said bolt and housing for locking said bolt in erect position, said locking means including interengaging parts respectively on said bolt and housing which interengage when said bolt is in erect position and is at one limit of its movement longitudinally of itself, said parts being disengaged by longitudinal movement of the erect bolt from said limit position, and means to bias said erect bolt toward said limit position and against disengaging movement.

.2. A dead-locking jamb bolt according to claim 1 in which one of said bolt and housing carries a lock projection and the other carries a keeper slot, said projection and slot being aligned for interengagement when said bolt is in erect position and being urged to such interengagement by said biasing means.

3. A dead-locking jamb bolt, comprising a box-like housing adapted to be flush-mounted in the face of a jamb, a bolt pivotally movable in said housing between an erect position in which it stands out from the jamb and a depressed position in which it lies within the boxlike housing below the jamb face, said bolt also having limited movement longitudinally of itself when in erect position, means to bias the bolt in one direction of such longitudinal movement, said bolt carrying a lateral lock projection and said housing being provided with a SlQt for said projection, said slot having an outer arcuate portion permitting free movement of said projection during pivotal movement of the bolt, and having a radial keeper portion to receive the projection in bolt-locking engagement when the bolt is erect, said projection being moved radially upon longitudinal displacement of the bolt, said biasing means urging the bolt in a displacement direction to engage the projection in said radial portion, and said bolt being manually movable in a displacement direction to release the projection.

4. A dead-locking jamb bolt, comprising a box-like housing adapted to be flush-mounted in the face of a jamb, a bolt pivotally movable in said housing between an erect position in which it stands out from the jamb and a depressed position in which it lies within the boxlike housing below the jamb face, said bolt also having limited movement longitudinally of itself when in erect position, means to bias the bolt in one direction of such longitudinal movement, said bolt having an end face in tangential relation to the pivot axis, and said biasing means comprising a yieldable leaf bearing against said end face when the bolt is erect, a latch boss on one of said face and leaf and a keeper slot in the other, the same being in locking engagement when said bolt is erect, said leaf being moved by longitudinal displacement of the bolt to release such locking engagement.

5. A dead-locking jamb bolt, comprising a housing, a bolt mounted for pivotal movement in said housing between depressed and erect positions and for limited 1ongitudinal displacement when in erect position, locking means between said bolt and housing and including interengaging elements respectively on said bolt and housing which interengage to prevent pivotal movement of the bolt from erect position when the erect bolt is in a position of longitudinal displacement, and means to bias the bolt to said position of displacement.

6. A dead-locking jamb bolt as defined in claim 5 in which said displacement moves the bolt radially of its pivot axis, and said locking means comprises a tongue on one of said bolt and its pivot support and a tonguereceiving groove on the other, which tongue and groove interengage upon such radial displacement to lock the bolt in erect position.

7. A dead-locking jamb bolt as defined in claim 5 in which the bolt is mounted on a fixed pivot pin, the pin hole having a slot and the pin having a tongue to enter said slot when the bolt is erect.

8. A dead-locking jamb bolt for blocking movement of a sliding panel, comprising a housing adapted to be mounted in a support at the edge of the panel, a bolt mounted for pivotal movement in said housing on an axis parallel with the direction of movement of the panel, said bolt having a depressed position and being pivotally movable in a plane across the path of panel movement to an erect position blocking said movement, said bolt also having limited radial displacement movement in said plane when in erect position, locking means for said bolt including interengageable parts respectively on the housing and bolt which engage to prevent pivotal movement of the bolt from erect position when the erect bolt is in a position of displacement, and means to bias the bolt to said position of displacement.

References Cited in the file of this patent UNITED STATES PATENTS 666,596 Breen Jan. 22, 1901 1,101,944 Mangin June 30, 1914 FOREIGN PATENTS 18,290 Great Britain 1905 

